1. Field of the Invention
The present invention relates to a method and apparatus for manufacturing a one end flange-less automobile wheel rim.
2. Description of Related Art
Recently, full face automobile wheels have become fashionable. In the full face automobile wheel, the outboard flange is integrally formed in the wheel disk and the inboard flange only is integrally formed in the rim so that the connection between the rim and the disk cannot be seen from outside when the wheel is mounted to an automobile.
Conventionally, this one end flange-less wheel rim is manufactured according to a method, steps of which are illustrated in FIG. 10. In the method, first, a rim 1 having flanges 2 and 3 on opposite ends thereof is roll-formed, and then a flange 2 formed at one end of the rim is cut with a margin for machining left at the rim, and finally the flange-less end 6 of the rim is machined. In this instance, the cut flange and removed margin will be scraps 4 and 5.
However, the conventional method has the following problems:
First, since the rim material has to include a portion corresponding to the flange which is cut after forming the rim, the yield of the material is low.
Second, since scrap is generated when the axially outboard side flange is cut after forming, the scrap has to be removed, which takes a considerably amount of work and time.
Third, cutting the axially outboard side flange is conducted manually, which lengthens the cycle time of the rim manufacture and lowers productivity.
Fourth, a cutting-off tool is needed for the cutting and the cutting-off tool has to be replaced by a new one. As a result, the manufacturing cost of the wheel rim increases.